P14.31 CMV reactivation in a cohort of newly-diagnosed glioblastoma patients treated with temozolomide chemoradiotherapy. A single center analysis

Abstract

Abstract BACKGROUND The Cytomegalovirus (CMV) is a ubiquitous herpes virus which infects 60–80 % of the population in Europe. Although the CMV usually remains latent, reactivation can occur in the context of an immunodepression, such as low CD4-lymphocyte levels in HIV patients. Glioblastoma (GBM) patients frequently show lymphopenia, which is related to both the immunosuppressive nature of the tumor and to the treatment with concomitant temozolomide (TMZ) and radiotherapy (RT). Surprisingly, the incidence of CMV reactivation in GBM patients has not been clearly studied so far. We report here our experience on CMV reactivation in a cohort of newly-diagnosed GBM patients, treated with RT and TMZ. We assessed the incidence of CMV reactivation in these patients and tried to identify risk factors for such reactivation. MATERIAL AND METHODS All consecutive patients with histologically confirmed malignant GBM recommended for temozolomide chemoradiotherapy in our institution from October 2013 to December 2015 were reviewed. In all patients, sex, age, Karnofsky performance status (KPS), lymphocyte level, serological CMV status and steroid dosages were recorded at the onset, and one month after completion of the concomitant radio-chemotherapy regimen. A CMV reactivation was defined by a detection of CMV DNA > 1000 copies/ml in the patient’s serum. RESULTS 103 patients meeting the analysis criteria were reviewed. Within these 103 patients, 34 patients (33%) had initial negative serology for CMV, and none of them developed a seroconversion after treatment with concomitant RT + TMZ. Among patients with positive IgG (n=69), 16 patients (23%) developed a positive viremia at one point during treatment with concomitant RT + TMZ. Age (>60 years), lymphocyte count before RT (<1500/mm3) and use of steroids were correlated with CMV reactivation (p<0.05 in univariate analysis). A positive CMV viremia during RT+TMZ did not impact the progression free survival (PFS) but was associated with a shorter overall survival (OS) when compared to the others patients (median: 12 months vs 15 months; p=0.04). No clinical symptoms suggestive of CMV infection were reported. CONCLUSION In this single center series, we showed that CMV reactivation occurs in 23% of the GBM patients having a positive serology for CMV. Reactivation was more frequent in older patients, with low lymphocyte counts and treated with steroids. A positive viremia was not associated with poor PFS, a fact that does not support a promoting role of CMV in glioma oncogenesis, which has been sometimes suggested. Yet, the group of patients with CMV reactivation showed a shorter OS, which might be related to an older age and /or poorer clinical conditions in this group.